1. Field of the Invention
The present invention relates to a distributed feedback type surface emitting laser using a two-dimensional photonic crystal.
2. Description of the Related Art
There has been known a surface emitting laser which uses a two-dimensional photonic crystal as a reflecting mirror, configures the two-dimensional photonic crystal itself as a laser resonator, generates laser amplification in a horizontal direction (in-plane direction), and extracts light in a vertical direction to a crystal surface thereof.
In particular, in a surface emitting laser using a nitride semiconductor which can emit light in the near-ultraviolet to green range, it is difficult to manufacture a commonly used distributed Bragg reflector, and thus a surface emitting laser using a two-dimensional photonic crystal has been actively studied.
As such a two-dimensional photonic crystal surface emitting laser, in order to improve light use efficiency, Japanese Patent Application Laid-Open No. 2003-273456 discloses a surface emitting laser which provides a light-reflecting region, around a periphery of the two-dimensional photonic crystal in a horizontal direction to the crystal surface thereof, in a vertical direction to a crystal surface of the two-dimensional photonic crystal.
According to this configuration, part of the light which attempts to leak outside in the horizontal direction (in-plane direction) from the two-dimensional photonic crystal is reflected inside by the light-reflecting region, which is expected to improve light use efficiency.